Sheet processing apparatus

Abstract

A sheet processing apparatus includes an aligning member and a shift conveying unit. The aligning member is movable in a width direction perpendicular to a sheet conveying direction and presses a sheet stack loaded on a sheet processing tray so as to align the sheet stack in the width direction. The unit is provided on the upstream side of the tray and conveys a sheet, shifting the sheet in the width direction. Being shifted by the unit, sheets are loaded at first and second loading positions on the tray. When sheets are loaded at the first loading position, the aligning member is moved to a first standby position corresponding to the first loading position in advance. When sheets are loaded at the second loading position, the aligning member is moved in advance to a second standby position corresponding to the second loading position.

1. A sheet processing apparatus comprising:
 a shift conveying unit that conveys a sheet in a sheet conveying direction and shifts the sheet in a width direction perpendicular to the sheet conveying direction; 
 a sheet processing tray on which sheets are loaded after being conveyed by the shift conveying unit, wherein by being shifted in the width direction by the shift conveying unit, the sheets are loaded at a first loading position and a further loading position that is offset from the first loading position in the width direction on the sheet processing tray; 
 an aligning member that is movable in the width direction and presses the sheet stack loaded on the sheet processing tray so as to align the sheet stack in the width direction; and 
 a discharge member that discharges the sheet stack aligned by the aligning member; 
 wherein if sheets are loaded at the first loading position, the aligning member is moved to a first standby position corresponding to the first loading position in advance and then moves from the first standby position in order to align the sheet stack loaded at the first loading position, and 
 wherein if sheets are loaded at the further loading position, the aligning member is moved in advance to a further standby position corresponding to the further loading position and then moves from the further standby position in order to align the sheet stack loaded at the further loading position. 
 
   
   
     2. The sheet processing apparatus according to  claim 1 , wherein the shift conveying unit includes a position detecting device that detects the position of the edge of a sheet to be shifted, and the shift distance of the sheet is controlled according to the position of the edge of the sheet detected by the position detecting device. 
   
   
     3. The sheet processing apparatus according to  claim 1 , further comprising a malfunction detecting device that detects whether there is a malfunction in the shift conveying unit, wherein when the malfunction detecting device detects a malfunction in the shift conveying unit, the distance of the aligning member at its standby position is set to a distance larger than the distance of the aligning member at the first standby position and the further position. 
   
   
     4. The sheet processing apparatus according to  claim 1 , wherein the shift distance of the sheet can be set according to sheet size. 
   
   
     5. The sheet processing apparatus according to  claim 1 , wherein the shift distance of the sheet can be set according to process mode. 
   
   
     6. The sheet processing apparatus according to  claim 1 , wherein the aligning member moves in order to align sheets every time sheets are loaded onto the sheet processing tray.